The invention relates to a safety device in the form of an airbag for motor vehicle occupants comprising an airbag which is located inflated in front of a vehicle occupant in response to a specified vehicle deceleration, and said airbag having outlet openings in its cover which permit the gas volume to be partially forced out, the airbag resting with a support surface against a vehicle curved windshield surface and having on an opposite side an impact surface for the vehicle occupant when inflated, said impact surface being approximately aligned in the vehicle transverse direction.
German Unexamined Published Application 3,505,927 discloses an airbag for the front passenger of motor vehicles, said airbag being inflated in front of the front passenger and intercepting with its impact surface the upper part of the body of a vehicle occupant thrown forwards in response to a specified vehicle deceleration. For this purpose, the airbag should be able to rest as far as possible with a support surface arranged on the opposite side against a windshield surface and to be supported there. In this respect, it is to be noted that a usual symmetrically constructed airbag with straight edges can be repelled, on the impact of the vehicle occupant, from a curved windscreen surface, as occurs markedly in particular in side regions of the motor vehicle near to the front support pillar. This results in a swivelling moment around a vertical axis being induced in the airbag, the airbag then swivelling out an impact surface, for the vehicle occupant out of a favorable position and throwing the vehicle occupant back in more unfavorable direction. In order to prevent this effect from occurring, the airbag described in the above-noted DOS 3,505,927 is of asymmetrical construction and matched to the shape of the windshield. This means a high production outlay for the airbag, the application possibilities of which has to be separately tested for each vehicle type, since a changed windshield curvature can to a large extent also make it necessary to change the shape of the airbag. This change must then have also already occurred if only the vertical position of a receiving container for mounting the airbag cover, e.g., a front passenger airbag in a dashboard panel, is changed, since then also the shape of the airbag cover already deviates from that of the windshield and the advantages of the matching no longer exist.
In German Published Unexamined Patent Application (DOS) 1,780,304, changeable openings in side parts of an airbag cover are provided, the intention being that an essentially constant pressure in the airbag should be maintained by means of said changeable openings if a vehicle occupant presses on the airbag cover.
An object of the invention is to provide an airbag safety device of the above-noted type which is favorable in terms of economics of manufacture, and which is appropriately matched to a curved windshield surface, so that the impact surface of the airbag is aligned for the vehicle occupant approximately in the vehicle transverse direction.
The object is achieved according to preferred embodiments of the invention by providing airbag venting openings configured to assure matching of the airbag to the curved windshield surface without inducing twisting of the airbag.
By means of the outlet openings asymmetrically arranged over an airbag surface with the outlet openings permitting the greatest emergence of gas in the region of the greatest windscreen curvature, it is achieved that the airbag, on being loaded by a vehicle occupant, can be purposefully more strongly compressed in this region and thus rests against the screen curvature, as a result of which the desired alignment of the impact surface for the vehicle occupant on the opposite side of the airbag in the vehicle transverse direction can be maintained.
This arrangement of the present invention has the result that the airbag can be produced in a uniform shape, which can be matched without a great degree of outlay to differently curved windscreen sections by means of a corresponding variation of the opening cross-sections of the outlet openings.
By means of the deliberate arrangement of outlet openings in side parts or on an airbag surface facing away from the vehicle occupant, the gas flowing out of the gas generator is prevented from being directed towards the vehicle occupant.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.